Regulation Of GLAST In The Retinal Mǖller Cells Of Mice By TGFα

Objective: To study the regulation of GLAST by TGFαin the retinal Muller cells of mice.Methods: (1) Retinal MUller cells of mouse at postnatal day 7-10 were cultured by tissue inoculation.(2) Cultured retinal Muller cells were divided into two groups:①TGFαgroup:cultured retinal Muller cells were maintained in different concentrations of TGFα(50ng/mol, 75ng/mol,125ng/mol and 150ng/mol) for 24 h in vitro;②Control group: cultured retinal Muller cells without TGFα.(3) The activity of GLAST in the retinal Muller cells was assayed through L-3~H-glutamate uptake detection. (4) The expression of GLASTmRNA in the retinal Muller cells was semi-quantified by RT-PCR. (5) The expression of GLAST protein in the retinal Muller cells was detected with immunocytochemical staining.Results: (1) All the concentrations of TGFαmentioned above increased the uptake of L-3~H-glutamate in the cultured retinal Muller cells. The effect of TGFαon L-3~H-glutamate accumulation was dose-dependent and got to maximal uptake (cpm/mg/mol.pro: 8434.14±191.69) at concentration of 125ng/mol, which was 266% of that in control group (cpm/mg/mol.pro: 3166.81±47.50). (2) The expressions of GLASTmRNA was up-regulated as the increase of the concentrations of TGFα. The 125ng/mol TGFαcaused a maximal increase in GLAST mRNA expression (0.85±0.13), which is quadruple than that in the control group (0.20±0.03). (3) Immunocytochemistry indicated that GLAST protein located in the cytoplasm and membrane of retinal Mullercells. The effect of 125ng/mol TGFαon expression of GLAST protein were higher than that in the control group,which were significant differences between these two groups (P＜0.05)Conclusion: TGFαcan increase GLAST activity through up-regulating the expression of GLASTmRNA and protein.